An Mi-17 helicopter with the Afghan 377th Rotary Wing Squadron flies from the northern Afghan town of Fayzabad to Kabul. / Jack Gruber, USA TODAY

by Jim Michaels, USA TODAY

by Jim Michaels, USA TODAY

WASHINGTON â?? The Pentagon is accelerating the deployment of mortars and artillery to Afghanistan's fledgling army in an effort to help compensate for the loss of American air power, which has proved devastating against the Taliban over the years.

The loss of American firepower after 2014 will be a key challenge for the Afghan force and highlights stark choices the White House is confronting as it shapes a follow-on force.

Afghan commanders are worried about its impact on operations.

"They certainly haven't missed the fact that the finest air force on the planet is going home," said Marine Gen. John Allen, who stepped down as top coalition commander in February and has retired.

But Allen said mortars, artillery and helicopter gunships will give Afghan forces quick access to their own firepower.

The Pentagon has said it will leave advisers and a counterterrorism force in Afghanistan after the combat mission ends. Air power would be available for remaining U.S. counterterrorism forces.

Afghan President Hamid Karzai has been critical of air attacks, accusing the coalition of mistakenly killing civilians. The White House has also been pushing to limit the size of the post-2014 force in Afghanistan, which restricts the amount of support Americans can supply, analysts say.

"There is enormous political pressure to get the numbers down," said Fred Kagan, an analyst at the American Enterprise Institute who has advised top commanders in Afghanistan and Iraq. Kagan said Karzai's criticism might also have played a role in the American decision.

The Pentagon has said the decision is based on a strategy to transition security responsibility to Afghan forces as American and coalition forces withdraw.

Afghanistan's own air force is not expected to be fully operational until 2016 at the earliest, the Pentagon said. Even when it is, it won't have near the capabilities of the U.S. military, which leads the world in delivering powerful munitions accurately.

The Afghans' main close air support plane, a turboprop Super Tucano, won't be fielded until mid-2014, Air Force Maj. Gen. H.D. Polumbo, the top coalition air commander, told reporters recently.

In the meantime, Allen said the coalition is taking a number of steps that will give Afghanistan's military a firepower advantage over the Taliban, including providing the additional mortars and arming their Mi-17 helicopters with rockets and gatling guns.

The additional firepower, which will be integrated into small units, will give Afghan troops the ability to respond quickly.

"The issue is having the right kind of combined arms capability," Allen said, referring to the tactics of coordinating firepower with the movement of troops on the ground.

Air power helped collapse the Taliban regime after the United States and its allies invaded Afghanistan in response to the September 2001 attacks. Since then, American airstrikes have helped give Afghan and coalition forces a critical advantage over the Taliban.

Taliban militants are unable to mass forces without risking a devastating attack, forcing militants to fight in small groups and resort to roadside bombs and terrorist strikes on civilian targets.

"U.S firepower is very intimidating to the Taliban," said David Barno, a retired three-star general who commanded coalition forces in Afghanistan and is now a senior adviser at the Center for a New American Security.

"Throughout this campaign, coalition air power has provided a critical asymmetric advantage," Polumbo said.

Some analysts worry the removal of air power will take a key advantage away from Afghan forces.

"It's incredibly important that Afghan security forces have access to this capability and that the Taliban know they have access to this capability," Kagan said.

"The Afghan security forces are happy to fight," he added. "They want to know they are going to win the fight at the end of the day. The nice thing about air support is it lets you end the discussion with the enemy."

Allen said by integrating mortars and artillery into Afghanistan's army, the coalition is providing a capability more in keeping with the Afghans style of fighting.

Afghan soldiers are particularly adept at mortars, a simple weapon system employed inside infantry units. Small mortars, such as the 60mm, can be packed on mules or carried in pieces by soldiers.

Already, as Afghan forces increasingly take the lead in operations, the coalition is backing off the frequency of air support.

Because of the concern over civilian or friendly casualties, regulations do not allow an Afghan unit to call for airstrikes unless a coalition air control team is accompanying the unit. Increasingly, Afghan forces are going out on their own and so lack the ability to call for coalition airstrikes.

Marine Maj. Gen. Charles "Mark" Gurganus, who recently returned to the United States after commanding coalition forces in southwest Afghanistan, said the coalition can currently provide the Afghans with air support if joint planning is conducted before an operation so a coalition team can be embedded with the Afghans.

"The trouble is if they go out and get into trouble we don't know where they are," Gurganus said. "We don't fire any weapons systems because one of their commanders gets in a little bit of a fight and runs out and says, 'I need fire support right now.' "